27821868 has 12 divisors (see below), whose sum is σ = 64917720. Its totient is φ = 9273952.

The previous prime is 27821867. The next prime is 27821879. The reversal of 27821868 is 86812872.

It is a tau number, because it is divible by the number of its divisors (12).

It is a Smith number, since the sum of its digits (42) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (27821861) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1159233 + ... + 1159256.

It is an arithmetic number, because the mean of its divisors is an integer number (5409810).

Almost surely, 2^27821868 is an apocalyptic number.

It is an amenable number.

27821868 is an abundant number, since it is smaller than the sum of its proper divisors (37095852).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

27821868 is a wasteful number, since it uses less digits than its factorization.

27821868 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2318496 (or 2318494 counting only the distinct ones).

The product of its digits is 86016, while the sum is 42.

The square root of 27821868 is about 5274.6438742345. The cubic root of 27821868 is about 303.0135819376.

The spelling of 27821868 in words is "twenty-seven million, eight hundred twenty-one thousand, eight hundred sixty-eight".